Bi-amp question


Ok... I have recently purchased a set of psb synchrony ones and a NAD M3 amp(180 wpc)... if were to add another amp, say a Rotel RB-1170(130 wpc) for bi-amping... which way would make the most sense to wire them up? NAD for the Highs and Rotel for the Lows? or vice versa???

I would obviously need to experiment with them to see which way sounds best to my ears... just wondering if there were any ground rules...
sbrooks32
DACT has a 10k, 0 to -12 dB in 0.5 dB steps, "fine tuning" attenuator that can tame different amps. Easy enough to add series resistance if required (50K for some tube preamps). Inline with the "stronger" amp after the Y. Another pair of IC's, a small project box (Goldpoint?) and a drill, a knob, 4 female RCAs, hook-up wire and a bit of soldering.

Don't try this with pots.
The concern over "different sounding amps" makes no sense. The drivers powered by the two amps are totally different technology, with sound characteristic differences far greater than that between two amps.
Correction: The "fine" attenuator only comes in single deck mono, so you would need two of them.

With monoblocks, that actually works better with the attenuators close to each amp, in separate enclosures.

Some "pro" amps have adjustable gain built in but it's probably just a cheap pot.
Rodman99999: "Both amps will still remain saddled with reproducing the full signal, from your preamp."

Well...yes and no. Certainly each amp is driven by the full-band signal from the preamp, but each amp doesn't drive the same full-range signal from the preamp. This is because each amp is driving only part of the speaker's crossover. The amp driving a low-frequency end is presented with a load that increases its resistance dramatically as the frequency rises, and each amp driving a high-frequency end is presented with a load that increases its resistance dramatically as the frequency lowers.

Then if one has an amp with great-sounding bass and edgy treble, use it as a bass-end amp, and if one has an amp with great-sounding MR and treble but is a bit wimpy in the bass, use it as a upper-frequency amp.

Of course, the biggest problem with passive biamping with different amps, that of matching the different Voltage gains, still remains if one doesn't already have gain controls on the higher-gain amp.

IMO passive biamping can be rewarding, but it's not for novices unless you don't care if the tonal balance of your speaker systems ends up badly inaccurate.
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I looked into this a while back, and for my situation it wasn't worth it. My thought was a tube amp for mids/trebble and a 200 Wpc SS amp for bass, which I had. I tried feeding both amps from the pre, so both reproducing the full bandwidth, and found no material benefit. BTW, my tube amp gas gain attenuators to match gains.

To do it right, I thought of adding a crossover between pre and amps, and had to take the speakers' passive crossover out (the bass and mids/hi). That was too much a hassle/risk and decided to leave it alone. Some people have speakers that make taking that crossover out much easier, and from a theoretical point of view actively biamping still makes sense to me...so might give it another try in the future.

Yet this configuration requires an additional crossover, an additional pair of ICs, 2 additional power cords...when you add it up I can't help but wonder how a more expensive amp driving full bandwidth would compare!

Hence, the dilema. Thanks for allowing me to share my confusion! :-)

cheers